Raman spectroscopy is a non-destructive technique that provides information about molecular structure and interactions by analyzing low-frequency vibrational modes. When monochromatic light interacts with a molecule, most light is elastically scattered (Rayleigh scattering) while a small amount is inelastically scattered, shifting to higher or lower frequencies (Raman scattering). Raman scattering provides molecular fingerprints that can be used to identify substances. Raman spectroscopy has applications in chemistry, materials science, geology, pharmaceuticals, and life sciences such as identifying compounds, studying molecular structure and reactions, and disease diagnosis. It is commonly used due to providing specific vibrational information about chemical bonds and symmetry.
Raman Spectroscopy - Principle, Criteria, Instrumentation and ApplicationsPrabha Nagarajan
Basic principle of Raman scattering- Difference between Rayleigh and Raman Scattering- Major criteria for Raman active in compounds,-Stroke's lines and Anti-stoke lines- Difference and between IR and Raman spectroscopy- Wide applications of Raman spectroscopy.
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Raman Spectroscopy - Principle, Criteria, Instrumentation and ApplicationsPrabha Nagarajan
Basic principle of Raman scattering- Difference between Rayleigh and Raman Scattering- Major criteria for Raman active in compounds,-Stroke's lines and Anti-stoke lines- Difference and between IR and Raman spectroscopy- Wide applications of Raman spectroscopy.
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NQR - DEFINITION - ELECTRIC FIELD GRADIENT - NUCLEAR QUADRUPOLE MOMENT - NUCLEAR QUADRUPOLE COUPLING CONSTANT - PRINCIPLE OF NQR - ENERGY OF INTERACTION - SELECTION RULE - FREQUENCY OF TRANSITION - APPLICATIONS
It contains the basic principle of Mossbauer Spectroscopy.
Recoil energy, Dopler shift.
The instrumentation of Mossbauer Spectroscopy.
Hyperfine interactions.
Photoelectron spectroscopy
- a single photon in/ electron out process
• X-ray Photoelectron Spectroscopy (XPS)
- using soft x-ray (200-2000 eV) radiation to
examine core-levels.
• Ultraviolet Photoelectron Spectroscopy (UPS)
- using vacuum UV (10-45 eV) radiation to
examine valence levels.
Nmr nuclear magnetic resonance spectroscopyJoel Cornelio
Basics of NMR. Suitable for UG and PG courses.
Includes principle, instrumentation, solvents. chemical shift and factors affecting it. Some problems. resolving agents, coupling constant and much more
Although the inelastic scattering of light was predicted by Adolf Smekal in 1923, it was not observed in practice until 1928. The Raman effect was named after one of its discoverers, the Indian scientist C. V. Raman, who observed the effect in organic liquids in 1928 together with K. S. Krishnan, and independently by Grigory Landsberg and Leonid Mandelstam in inorganic crystals. Raman won the Nobel Prize in Physics in 1930 for this discovery. The first observation of Raman spectra in gases was in 1929 by Franco Rasetti.
NQR - DEFINITION - ELECTRIC FIELD GRADIENT - NUCLEAR QUADRUPOLE MOMENT - NUCLEAR QUADRUPOLE COUPLING CONSTANT - PRINCIPLE OF NQR - ENERGY OF INTERACTION - SELECTION RULE - FREQUENCY OF TRANSITION - APPLICATIONS
It contains the basic principle of Mossbauer Spectroscopy.
Recoil energy, Dopler shift.
The instrumentation of Mossbauer Spectroscopy.
Hyperfine interactions.
Photoelectron spectroscopy
- a single photon in/ electron out process
• X-ray Photoelectron Spectroscopy (XPS)
- using soft x-ray (200-2000 eV) radiation to
examine core-levels.
• Ultraviolet Photoelectron Spectroscopy (UPS)
- using vacuum UV (10-45 eV) radiation to
examine valence levels.
Nmr nuclear magnetic resonance spectroscopyJoel Cornelio
Basics of NMR. Suitable for UG and PG courses.
Includes principle, instrumentation, solvents. chemical shift and factors affecting it. Some problems. resolving agents, coupling constant and much more
Although the inelastic scattering of light was predicted by Adolf Smekal in 1923, it was not observed in practice until 1928. The Raman effect was named after one of its discoverers, the Indian scientist C. V. Raman, who observed the effect in organic liquids in 1928 together with K. S. Krishnan, and independently by Grigory Landsberg and Leonid Mandelstam in inorganic crystals. Raman won the Nobel Prize in Physics in 1930 for this discovery. The first observation of Raman spectra in gases was in 1929 by Franco Rasetti.
Experimentally Raman Spectroscopy was discovered by an Indian Physicist C. V. Raman in 1928 with his collogue .
Theoretically, similar Phenomenon inelastic scattering predicted by an Austrian Physicist Adolf Smekal in 1923.
According to Smekal, might be dispersed in-elastically by molecules in addition to the origin wavelength, shorter and longer wavelengths would be present. They further demonstrated that the frequency shift between incoming and scattered light is caused by the difference in energy between two states of the molecules.
SPECTROSCOPY is defined as the study of the interactions between radiations and matter as function of wavelength λ .
Interactions with particle radiation or a response of a material to an altering field
or varying frequency.
SPECTRUM : A plot of the response as a function of wavelength or more commonly frequency is referred to as spectrum.
SPECTROMETRY : It is measurement of these responses and an instrument which performs such measurements is a spectrophotometer or spectrograph, although
these terms are more limited in use to original field of optics from which the
concept sprang.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Deep Behavioral Phenotyping in Systems Neuroscience for Functional Atlasing a...Ana Luísa Pinho
Functional Magnetic Resonance Imaging (fMRI) provides means to characterize brain activations in response to behavior. However, cognitive neuroscience has been limited to group-level effects referring to the performance of specific tasks. To obtain the functional profile of elementary cognitive mechanisms, the combination of brain responses to many tasks is required. Yet, to date, both structural atlases and parcellation-based activations do not fully account for cognitive function and still present several limitations. Further, they do not adapt overall to individual characteristics. In this talk, I will give an account of deep-behavioral phenotyping strategies, namely data-driven methods in large task-fMRI datasets, to optimize functional brain-data collection and improve inference of effects-of-interest related to mental processes. Key to this approach is the employment of fast multi-functional paradigms rich on features that can be well parametrized and, consequently, facilitate the creation of psycho-physiological constructs to be modelled with imaging data. Particular emphasis will be given to music stimuli when studying high-order cognitive mechanisms, due to their ecological nature and quality to enable complex behavior compounded by discrete entities. I will also discuss how deep-behavioral phenotyping and individualized models applied to neuroimaging data can better account for the subject-specific organization of domain-general cognitive systems in the human brain. Finally, the accumulation of functional brain signatures brings the possibility to clarify relationships among tasks and create a univocal link between brain systems and mental functions through: (1) the development of ontologies proposing an organization of cognitive processes; and (2) brain-network taxonomies describing functional specialization. To this end, tools to improve commensurability in cognitive science are necessary, such as public repositories, ontology-based platforms and automated meta-analysis tools. I will thus discuss some brain-atlasing resources currently under development, and their applicability in cognitive as well as clinical neuroscience.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
This pdf is about the Schizophrenia.
For more details visit on YouTube; @SELF-EXPLANATORY;
https://www.youtube.com/channel/UCAiarMZDNhe1A3Rnpr_WkzA/videos
Thanks...!
4. Sir Chandrasekhara Venkata Raman
November 7, 1888 – November 21, 1970
Carried out ground-breaking work in the field of light
scattering, which earned him the 1930 Nobel prize for
Physics
• Discovered the “Raman effect”.
• In 1954, India honoured him with its highest
civilian award, the Bharat Ratna.
Also independent observations by
Grigory Landsberg and Leonid Mandelstam.
5. • Raman Spectroscopy is a non-destructive chemical analysis technique
which is used to analyze vibrational, rotational, and other low-
frequency modes in a system, providing information about chemical
structure, crystallinity and molecular interactions.
• When a monochromatic radiation of definite frequency (ʋ ) is passed
through a substance, the light is scattered at right angles to the incident
radiation containing lines of-
i. Incident frequencies
ii. Certain discrete frequencies above or below that of incident
radiation..
• The transmitted lines with same frequency as that of incident radiation
is called Rayleigh scatter.
• However a small amount of light (typically 0.0000001) scattered at
different frequency (or wavelength) is called Raman Scatter.
7. Theory of Raman spectra.
When a monochromatic beam is passed through a scatterer (liquid or gas), small
fraction of light is scattered due to collision between molecules of substance and
photons of light. Two cases may arise depending upon whether a collision between
a photon and molecules in it’s ground state is elastic or inelastic in nature.
Case 1- if the collision is elastic – this lead to the appearance of unmodified lines
(or unmodified frequency of light) in the scattered beam and this explain Rayleigh
scattering.
Case 2 - if the collision is inelastic – there will be exchange or transfer of energy
between the scattering molecules and the incident photon leading to the Raman
scattering with the two cases.-
1. the molecule absorbs energy from the incident photon and reaches a higher
rotational vibrational state after excitation and emission of photon. Thus the
energy of emitted photon becomes less, hence frequency of scattering lines is
less than that of incident light. This gives stroke's line of Raman spectra.
2. the molecule imparts some of its intrinsic energy to incident photon ,the
emitted photon has higher energy which corresponds to anti stokes line of
raman spectra where frequency of scattering lines is more than that of incident
light. 7
8. Energy Scheme for Photon Scattering
Rayleigh
Scattering
(elastic)
Stokes
Scattering
Anti-Stokes
Scattering
h 0
h 0
h 0 h
h
0
m
h 0+h
m
E0+h
E0
m
Raman
(inelastic)
The Raman effect comprises a very small fraction,
about 1 in 107 of the incidentphotons.
Virtual
State
IR
Absorption
Energy
9. Stokes lines Anti Stokes lines
• The frequency of scattered lines is
more than that of incident light.
• Caused by molecules at higher
energy level which are less
populated.
• These are less intense with low
intensity of absorption.
• At high temperature, molecules
are raised to higher energy state,
thus these gradually increases and
become prominent.
• The frequency of scattered lines
is less than that of incident light
• Caused by molecule at lower
energy level which is more
populated.
• These are more intense with high
intensity of absorption.
• At low temperature, these takes
place more frequently.
Stokes Vs Anti Stoke’s lines
10. The difference between the frequency of the incident light
and that of scattered light is constant and it depends only
on the nature of substance. It is completely independent of
the frequency of incident light.
If ʋ o is the frequency of incident light and ʋ r is the
frequency of scattered light, then
θʋ = [ ʋ o - ʋ r }
This difference is called the Raman shift.
The various observations made by Raman are called Raman
effect and the spectrum obtained is called Raman spectrum.
RAMAN EFFECT
12. Mutual Exclusion Principle
Z
Symmetric molecules Based on polarisability
O = C = O O = C = O
Raman active
IR inactive
Raman inactive
IR active
According to the principle, ‘”All vibrations of a
molecule, with a centre of symmetry, which are
Raman active are infra-red inactive and vice versa”.
+ - +
O = C = O
Raman inactive
IR active
13. Differences between IR and Raman
methodsS.NO
Raman spectra IR spectra
01 It is due to the scattering of light
by the vibrating molecules.
It is the result of absorption of
light by vibrating molecules.
02 The vibration in Raman is active if
it causes a change in polarisability.
Vibration is IR active if there is
change in dipole moment.
03 Gives an indication of covalent
character in the molecule.
Gives an indication of ionic
character in the molecule.
04 Water can be used as a solvent. Water cannot be used due to it
is opaque to IR.
05 Can be obtained for a compound in
all three states.
IR spectra is quite diffused in
liquid and solid state.
14. Applications of Raman
spectroscopy
• Raman spectroscopy is commonly used in chemistry, since
vibrational information is specific to the chemical bonds and
symmetry of molecules.Therefore, it provides a fingerprint by
which the molecule can be identified.
• Raman spectroscopy is helps in studying the structure of
molecule and also the structural changes which occur due to
association, dissociation and solvation, study the kinetics of fast
reactions.
SOMEOFTHE IMPORTANTAPPLICATIONS ARE-
Elucidation of molecular structure
Nature of chemical bond
Quantitative analysis of mixture
Mechanism of tautomerism
15. Applications of Raman
spectroscopyCarbon Materials
Purity of CNTs
Specifying sp2 and sp3 structure in
carbon materials
Geology and Mineralogy
Gemstone and mineral identification
Fluid inclusions
Mineral and phase distribution in rock
sections
Pharmaceuticals
Compound distribution in tablets
Polymorphic forms
Contaminant identification
Life Sciences
Bio-compatibility
DNA/RNA analysis
Drug/cell interactions
Disease diagnosis